Dyphylline USP Powder
Dyphylline is a xanthine derivative with pyrimidine structure, used as a theophylline alternative in bronchodilators. HTS 2933.59.70.00 applies to this aromatic heterocyclic compound listed in U.S. note 3. It is imported as high-purity USP grade.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If containing epoxide or cyclic structure emphasized
Chapter notes exclude certain ring structures from 2933, moving to 2932.
If classified by carboxamide function
Nitrogen function headings (2924) may take precedence over heterocycle for some derivatives.
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Import Tips & Compliance
• Ensure chiral purity documentation if enantiomer-specific
• Avoid retail packaging to stay in chemical classification vs
• Chapter 30
• Test for related substances per USP monograph before export
Related Products under HTS 2933.59.70.00
Aminophylline USP
Aminophylline is a heterocyclic compound containing a xanthine (purine) structure with pyrimidine rings, used as a bronchodilator for asthma treatment. It falls under HTS 2933.59.70.00 as an aromatic pyrimidine derivative listed in additional U.S. note 3 to section VI for specific organic chemicals. This classification applies to its pure chemical form for pharmaceutical use.
Theobromine Powder
Theobromine is a methylxanthine alkaloid with fused pyrimidine rings in its purine structure, used in pharmaceuticals and as a chemical intermediate. Classified under HTS 2933.59.70.00 due to its aromatic nature and inclusion in additional U.S. note 3 to section VI. It qualifies as a separate chemically defined heterocyclic compound.
Caffeine Anhydrous USP
Caffeine anhydrous is a purine alkaloid featuring pyrimidine rings, used in pharmaceuticals, energy products, and as a chemical standard. It is covered by HTS 2933.59.70.00 as an aromatic heterocyclic compound described in additional U.S. note 3 to section VI. The classification reflects its chemically defined structure.
Paraxanthine Reference Standard
Paraxanthine is a caffeine metabolite with a xanthine (pyrimidine-containing) structure, supplied as analytical reference material. Falls under HTS 2933.59.70.00 for aromatic pyrimidines listed in additional U.S. note 3. Used in lab research and pharma development.
Theophylline Monohydrate
Theophylline monohydrate is a methylxanthine with pyrimidine rings, used in respiratory medications. Classified in HTS 2933.59.70.00 as an aromatic compound per additional U.S. note 3 to section VI. The hydrate form remains a separate chemically defined organic compound.
Proxyphylline Pharmaceutical Grade
Proxyphylline, a hydroxyethyltheophylline with pyrimidine rings, serves as a mild bronchodilator. Covered under HTS 2933.59.70.00 for its aromatic pyrimidine structure in additional U.S. note 3. Supplied for API manufacturing.